When emerging syslog-ng glib-2 gets pulled in. gobject builds a .glib-marshal that is linked against libglib-2.0.so. lib(64)/libglib-2.0.so however isn't contained int he x86_64 stage3 tarball, it only comes with lib32/libglib-2.0.so which gobject doesn't really care to look for. Since the handbook only mentions to emerge syslog-ng, this isn't accounted for.
I copied a libglib-2.0 from a diff x86_64 box to satisfy the emerge.
It's mindboggling how glib2 can depend on itself anyway. How would this work out on a ... LFS box where you build glib for the first time?
Steps to Reproduce:
We need a failing build.log to figure out what's going on.